The present invention relates to disc drive data storage systems and, more particularly, to a disc drive data storage system having a slider that reduces particulate contamination at the head-disc interface.
Disc drives of the xe2x80x9cWinchesterxe2x80x9d and optical types are well known in the industry. Such drives use rigid discs, which are coated with a magnetizable medium for storage of digital information in a plurality of circular, concentric data tracks. The discs are mounted on a spindle motor which causes the discs to spin and the surfaces of the discs to pass under respective hydrodynamic (e.g. air) bearing disc head sliders. The sliders carry transducers which write information to and read information from the disc surfaces.
An actuator mechanism moves the sliders from track-to-track across the surfaces of the discs under control of electronic circuitry. The actuator mechanism includes a track accessing arm and a suspension for each head gimbal assembly. The suspension includes a load beam and a gimbal. The load beam provides a load force which forces the slider toward the disc surface. The gimbal is positioned between the slider and the load beam, or is integrated in the load beam, to provide a resilient connection that allows the slider to pitch and roll while following the topography of the disc.
The slider has a bearing surface which faces the disc surface. As the disc rotates, the disc drags air under the slider and along the bearing surface in a direction approximately parallel to the tangential velocity of the disc. As the air passes beneath the bearing surface, air compression along the air flow path causes the air pressure between the disc and the bearing surface to increase, which creates a hydrodynamic lifting force that counteracts the load force and causes the slider to lift and fly above or in close proximity to the disc surface.
One of the major mechanical failure modes for disc drives is particle contamination. During operation of the disc drive, particles residing on the disc surface or carried along the air flow path between the slider and disc can cause physical damage to the head-disc interface and interfere with read and write operations. For example, as the slider passes over a debris particle, the slider can cause the particle to become embedded within the disc surface or can drag or roll the particle along the disc surface causing damage to the magnetic properties of the disc surface. Particles passing between the head and disc can also cause physical damage to the transducer carried by the slider. In addition, such particles can cause a temporary change in the flying attitude of the slider relative to the disc surface which can temporarily interfere with read and write operations.
Numerous proposed solutions to contamination have been implemented or attempted. These solutions typically include re-circulation filters, breather filters, the use of special coating materials that do not particulate, or the use of air bearing designs that reduce the impact of particulate contamination on the head-disc performance. For example, certain air bearing designs have been developed that attempt to divert debris particles along a preferential air flow path, between the slider and the disc and away from the transducer. However, these solutions have had limited success.
U.S. Pat. No. 4, 996,614 discloses a magnetic head having a leading end stepped portion for causing a vortex of air stream so as to take dust away from the disc surface. However, the stepped portion is not designed for deflecting particles away from the head-disc interface that are carried by the air flow. These particles can become deflected downward, toward the head-disc interface due to a substantial overhang created along the leading edge by the stepped portion.
A slider is therefor desired, that is effective in reducing particulate contamination at the head-disc interface due to particles carried by the air flow.
One aspect of the present invention is directed to a disc head slider having a slider body with a disc-facing surface and a leading surface adjacent to the disc facing surface. The disc facing surface has leading-most edge and first and second side edges. A bearing surface is formed on the disc facing surface. A debris deflection surface is formed along the leading surface, which is spaced vertically from the leading-most edge with respect to the disc facing surface and has a tangent that forms an angle with the bearing surface of less than ninety degrees.
Another aspect of the present invention is directed to a disc head slider having a slider body with a disc-facing surface and a leading surface adjacent to the disc facing surface. The disc facing surface has a leading-most edge, a trailing edge and first and second side edges. A bearing surface is formed on the disc facing surface. A debris collection recess is formed on the leading surface. The debris collection recess is vertically spaced from the leading-most edge and extends along a portion of the leading-most edge.
Yet another aspect of the present invention is directed to a disc drive which includes a data storage disc and a slider. The data storage disc has a recording surface which is rotatable about a central axis. The slider is supported relative to the recording surface for communicating with the recording surface through a slider-disc interface. The slider directs debris particles encountered along the recording surface away from the slider-disc interface in a non-downward vertical direction along a leading surface of the slider.
Yet another aspect of the present invention is directed to a method of fabricating a disc head slider. The method includes providing a slider body having a leading surface and a disc-facing surface. The disc-facing surface has a leading most edge extending along the leading surface. The method further includes forming a debris-deflection surface on the leading surface, which is spaced vertically from and extends along a portion of the leading-most edge and is oriented to deflect debris encountered at the leading surface away from the disc facing surface.